Cationice

Cationice is a term used in speculative discussions of ice-like materials to describe solid phases in which mobile cations are incorporated into the hydrogen-bond network of water ice. Such a phase would be an electrically conducting solid, unlike ordinary ice, which is a poor conductor of ions. The concept is not widely adopted as a standard material designation, and there is no confirmed experimental realization under normal conditions; most work is theoretical or computational, outlining possible structures and ion-transport mechanisms.

Possible structures include interstitial or substitutional incorporation of metal cations into high-pressure ice polymorphs, or stabilization of cation-containing clathrate hydrates. Ion insertion could occur during saline freezing or under conditions that promote lattice defects. Conduction is envisioned to occur via hopping between sites, with transport enhanced by channels or disorder within the lattice.

Predicted properties depend on pressure, temperature, and cation identity. Models often forecast measurable ionic conductivity at low temperatures and high pressure, along with anisotropic transport and elevated activation barriers at ambient conditions. Experimental evidence remains limited, and creating a stable, macroscopic cationice phase under practical conditions remains a major challenge.

If realized, cationice would advance understanding of ion transport in confined water networks and could inform the design of solid electrolytes for extreme environments or planetary ices. See also: Ice, Clathrate hydrates, Solid electrolytes, Ion conduction.